I have xampp on the VPS and apache and all that stuff is running and when I enter the VPS's IP on the browser(on the VPS), it loads the xampp content(htdocs). But whenever I try it on my computer or a friends it doesn't load?

Which VPS Software are you using, on which Windows is it hosted?What is the VPS IP?How is the VPS IP connected to the Windows host (NAT, Bridge,...)?Is the VPS running in your LAN?Is your computer running in the same LAN?How is your LAN connected to the Internet?How is the friends computer conntected to the Internet?